The present invention relates to suction discs and relates more particularly to a magnetic rubber suction disc for detachably securing an alarming device to a metal surface.
A movable alarming device may have a magnetic iron fastened in the bottom edge of the casing thereof so that it can be conveniently attached to the metal plate of the body of a motor vehicle. The coating on a motor vehicle's body may be scrapped off by the magnetic iron of a movable alarming device easily during the process of mounting or dismounting. Further, a movable alarming device of the said type may be caused to drop from a metal surface by a vibrating force or strong wind force.